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Cell Feb 2021Dopamine receptors, including D1- and D2-like receptors, are important therapeutic targets in a variety of neurological syndromes, as well as cardiovascular and kidney...
Dopamine receptors, including D1- and D2-like receptors, are important therapeutic targets in a variety of neurological syndromes, as well as cardiovascular and kidney diseases. Here, we present five cryoelectron microscopy (cryo-EM) structures of the dopamine D1 receptor (DRD1) coupled to Gs heterotrimer in complex with three catechol-based agonists, a non-catechol agonist, and a positive allosteric modulator for endogenous dopamine. These structures revealed that a polar interaction network is essential for catecholamine-like agonist recognition, whereas specific motifs in the extended binding pocket were responsible for discriminating D1- from D2-like receptors. Moreover, allosteric binding at a distinct inner surface pocket improved the activity of DRD1 by stabilizing endogenous dopamine interaction at the orthosteric site. DRD1-Gs interface revealed key features that serve as determinants for G protein coupling. Together, our study provides a structural understanding of the ligand recognition, allosteric regulation, and G protein coupling mechanisms of DRD1.
Topics: Allosteric Regulation; Allosteric Site; Amino Acid Motifs; Amino Acid Sequence; Binding Sites; Catechols; Cryoelectron Microscopy; Fenoldopam; GTP-Binding Protein alpha Subunits, Gs; HEK293 Cells; Humans; Ligands; Models, Molecular; Protein Multimerization; Receptors, Dopamine D1; Receptors, Dopamine D2; Signal Transduction; Structural Homology, Protein
PubMed: 33571432
DOI: 10.1016/j.cell.2021.01.028 -
Journal of Vascular Surgery Aug 2011Contrast-induced nephropathy (CIN) has been extensively studied since the 1950s due, in part, to its devastating adverse events. The intellectual push for additional... (Review)
Review
Contrast-induced nephropathy (CIN) has been extensively studied since the 1950s due, in part, to its devastating adverse events. The intellectual push for additional investigation into pathogenesis and prevention has heightened in recent years due to increased utilization of contrast enhanced imaging studies. Lack of a universal CIN definition and varied glomerular filtration rate markers have resulted in a varied reported incidence. Risk assessment and risk reduction strategies have evolved over the past several years. Current evidence supports volume supplementation before the administration of intravascular contrast to reduce the hazard of CIN. Other strategies to reduce the risk of CIN, including low osmolar contrast media, N-acetylcysteine, and intrarenal fenoldopam therapy, have variable levels of evidence, and further randomized trials are necessary.
Topics: Acetylcysteine; Antioxidants; Contrast Media; Evidence-Based Medicine; Fenoldopam; Fluid Therapy; Humans; Kidney Diseases; Risk Assessment; Risk Factors; Treatment Outcome; Vasodilator Agents
PubMed: 21741789
DOI: 10.1016/j.jvs.2011.04.047 -
Journal of Geriatric Cardiology : JGC Jul 2018Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The... (Review)
Review
Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The clinical presentation of hypertensive crises is quite variable in elderly patients, and clinicians must be suspicious of non-specific symptoms. Managing hypertensive crises in elderly patients needs meticulous knowledge of the pathophysiological changes in them, pharmacological options, pharmacokinetics of the medications used, their side effects, and their interactions with other medications. Clevidipine, nicardipine, labetalol, esmolol, and fenoldopam are among the preferred choices in the elderly due to their efficacy and tolerability. Nitroprusside, hydralazine, and nifedipine should be avoided, unless there are no other options available, due to the high risk of complications and unpredictable responses.
PubMed: 30364798
DOI: 10.11909/j.issn.1671-5411.2018.07.007 -
Clinical Journal of the American... Oct 2021AKI is a common complication after pediatric cardiac surgery and has been associated with higher morbidity and mortality. We aimed to compare the efficacy of available... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVES
AKI is a common complication after pediatric cardiac surgery and has been associated with higher morbidity and mortality. We aimed to compare the efficacy of available pharmacologic and nonpharmacologic strategies to prevent AKI after pediatric cardiac surgery.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS
PubMed/MEDLINE, Embase, Cochrane Controlled Trials Register, and reference lists of relevant articles were searched for randomized controlled trials from inception until August 2020. Random effects traditional pairwise, Bayesian network meta-analyses, and trial sequential analyses were performed.
RESULTS
Twenty randomized controlled trials including 2339 patients and 11 preventive strategies met the eligibility criteria. No overall significant differences were observed compared with control for corticosteroids, fenoldopam, hydroxyethyl starch, or remote ischemic preconditioning in traditional pairwise meta-analysis. In contrast, trial sequential analysis suggested a 80% relative risk reduction with dexmedetomidine and evidence of <57% relative risk reduction with remote ischemic preconditioning. Nonetheless, the network meta-analysis was unable to demonstrate any significant differences among the examined treatments, including also acetaminophen, aminophylline, levosimendan, milrinone, and normothermic cardiopulmonary bypass. Surface under the cumulative ranking curve probabilities showed that milrinone (76%) was most likely to result in the lowest risk of AKI, followed by dexmedetomidine (70%), levosimendan (70%), aminophylline (59%), normothermic cardiopulmonary bypass (57%), and remote ischemic preconditioning (55%), although all showing important overlap.
CONCLUSIONS
Current evidence from randomized controlled trials does not support the efficacy of most strategies to prevent AKI in the pediatric population, apart from limited evidence for dexmedetomidine and remote ischemic preconditioning.
Topics: Acute Kidney Injury; Adrenergic alpha-2 Receptor Agonists; Age Factors; Bayes Theorem; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Child, Preschool; Dexmedetomidine; Female; Humans; Infant; Infant, Newborn; Ischemic Preconditioning; Male; Network Meta-Analysis; Randomized Controlled Trials as Topic; Risk Assessment; Risk Factors; Time Factors; Treatment Outcome
PubMed: 34620647
DOI: 10.2215/CJN.05800421 -
BMJ Clinical Evidence Mar 2011Acute renal failure is characterised by abrupt and sustained decline in glomerular filtration rate, which leads to accumulation of urea and other chemicals in the blood.... (Review)
Review
INTRODUCTION
Acute renal failure is characterised by abrupt and sustained decline in glomerular filtration rate, which leads to accumulation of urea and other chemicals in the blood. The term acute kidney injury has been introduced to encompass a wide spectrum of acute alterations in kidney function from mild to severe. Acute kidney injury is classified according to the RIFLE criteria, in which a change from baseline serum creatinine or urine output determines the level of renal dysfunction.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of interventions to prevent acute kidney injury in people at high risk? What are the effects of treatments for critically ill people with acute kidney injury? We searched: Medline, Embase, The Cochrane Library, and other important databases up to December 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 82 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: albumin supplementation plus loop diuretics (intravenous), aminoglycosides, aminophylline, amphotericin B, calcium channel blockers, contrast media, dialysis membranes, dopamine, early versus late dialysis, extended daily dialysis, fenoldopam, loop diuretics, mannitol, N-acetylcysteine, natriuretic peptides, renal replacement therapy, sodium bicarbonate-based fluids, sodium chloride-based fluids, and theophylline.
Topics: Acetylcysteine; Acute Kidney Injury; Contrast Media; Creatinine; Glomerular Filtration Rate; Humans; Renal Dialysis
PubMed: 21443811
DOI: No ID Found -
Journal of Pediatric Intensive Care Jun 2014Contrast-induced nephropathy (CIN) remains a common and potentially serious complication in at risk patients after exposure to contrast agents. Risk factors for CIN... (Review)
Review
Contrast-induced nephropathy (CIN) remains a common and potentially serious complication in at risk patients after exposure to contrast agents. Risk factors for CIN include chronic kidney disease, hypotension, diabetes mellitus, recent previous exposure to contrast and all of these are potentially additive. Therefore, careful pre-procedural risk stratification is important. In high-risk patients, contrast should be avoided if possible. If avoidance is not possible, the volume of contrast should be minimized and the type of contrast used should if possible be non-ionic iso-osmolar contrast. In view of the clinical importance of CIN, numerous potential risk-reduction strategies have been evaluated. Adequate intravenous volume expansion with isotonic crystalloid (1.0-1.5 mL/kg per hr) for 3-12 hr before the procedure and continued for 6-24 hr afterward can lessen the probability of CIN in patients at risk. But there are insufficient data on oral fluids as a preventive strategy. Nephrotoxic drugs should be withdrawn before contrast administration in patients at risk for CIN. No adjunctive medical or mechanical treatment has been proved to be efficacious in reducing risk for CIN including prophylactic hemodialysis and hemofiltration, N-acetylcysteine, fenoldopam, dopamine, calcium channel blockers, atrial natriuretic peptide, and L-arginine. The CIN Consensus Working Panel considered that, of the pharmacologic agents that have been evaluated, theophylline, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), ascorbic acid, and prostaglandin E deserve further evaluation.
PubMed: 31214451
DOI: 10.3233/PIC-14090 -
Nature Communications Jun 2022Dopamine receptors are widely distributed in the central nervous system and are important therapeutic targets for treatment of various psychiatric and neurological...
Dopamine receptors are widely distributed in the central nervous system and are important therapeutic targets for treatment of various psychiatric and neurological diseases. Here, we report three cryo-electron microscopy structures of the D1 dopamine receptor (D1R)-Gs complex bound to two agonists, fenoldopam and tavapadon, and a positive allosteric modulator LY3154207. The structure reveals unusual binding of two fenoldopam molecules, one to the orthosteric binding pocket (OBP) and the other to the extended binding pocket (EBP). In contrast, one elongated tavapadon molecule binds to D1R, extending from OBP to EBP. Moreover, LY3154207 stabilizes the second intracellular loop of D1R in an alpha helical conformation to efficiently engage the G protein. Through a combination of biochemical, biophysical and cellular assays, we further show that the broad conformation stabilized by two fenoldopam molecules and interaction between TM5 and the agonist are important for biased signaling of D1R.
Topics: Cryoelectron Microscopy; Dopamine; Dopamine Agonists; Fenoldopam; Ligands; Receptors, Dopamine D1
PubMed: 35676276
DOI: 10.1038/s41467-022-30929-w -
Fenoldopam to prevent acute kidney injury after major surgery-a systematic review and meta-analysis.Critical Care (London, England) Dec 2015Acute kidney injury (AKI) after surgery is associated with increased mortality and healthcare costs. Fenoldopam is a selective dopamine-1 receptor agonist with... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Acute kidney injury (AKI) after surgery is associated with increased mortality and healthcare costs. Fenoldopam is a selective dopamine-1 receptor agonist with renoprotective properties. We conducted a systematic review and meta-analysis of randomised controlled trials comparing fenoldopam with placebo to prevent AKI after major surgery.
METHODS
We searched EMBASE, PubMed, meta-Register of randomised controlled trials and Cochrane CENTRAL databases for trials comparing fenoldopam with placebo in patients undergoing major surgery. The primary outcome was incidence of new AKI. Secondary outcomes were requirement for renal replacement therapy and hospital mortality.
RESULTS
Eighty-three publications were screened; 23 studies underwent full data extraction and scoring. Six trials were suitable for inclusion in the data synthesis (total of 507 subjects undergoing cardiovascular surgery, partial nephrectomy, liver transplant surgery). Five studies were rated at high risk of bias. Data on post-operative incidence of AKI were available in five of the six trials (total of 471 patients) but definitions of AKI varied between studies. Of the 238 patients receiving fenoldopam, 45 (18.9%) developed AKI compared to 62 (26.6%) of the 233 patients who received placebo (p = 0.004, I (2) = 0 %; random-effects model odds ratio 0.46, 95% confidence interval 0.27-0.79). In patients treated with fenoldopam, there was no difference in renal replacement therapy (n = 478; p = 0.11, I (2) = 47%; fixed-effect model odds ratio 0.27, 95% confidence interval 0.06-1.19) or hospital mortality (p = 0.60, I (2) = 0 %; fixed-effect model odds ratio 1.0, 95% confidence interval 0.14-7.37).
CONCLUSIONS
In this analysis, peri-operative treatment with fenoldopam was associated with a significant reduction in post-operative AKI but it had no impact on renal replacement therapy or hospital mortality. Equipoise remains for further large trials in this area since the studies were conducted in three types of surgery, the majority of studies were rated at high risk of bias and the criteria for AKI varied between trials.
Topics: Acute Kidney Injury; Fenoldopam; Hospital Mortality; Humans; Surgical Procedures, Operative
PubMed: 26703329
DOI: 10.1186/s13054-015-1166-4